diff --git a/help/Prop.md b/help/Prop.md
index 9a7ca90..70d1480 100644
--- a/help/Prop.md
+++ b/help/Prop.md
@@ -1,6 +1,6 @@
 # *Prop* class reference
 
-*Prop* is an interface (base class) implemented by 3 classes:
+*Prop* (see <a href="https://github.com/xcape-io/ArduinoProps/blob/master/src/Prop.h" target="_blank">`Prop.h`</a>) is an interface (base class) implemented by 3 classes:
 * ***BridgeProp*** for Yun board and Yun shield
 * ***EthernetProp*** for Ethernet shield
 * ***WifiProp*** for WiFiNINA boards
@@ -14,10 +14,10 @@ Each constructor implement the ***Prop*** interface:
 * `Props(const char* client_id, const char* in_box, const char* out_box, const char* broker, const int port)`
 ```csharp
 BridgeProp prop(u8"Arduino Blink", // as MQTT client id, should be unique per client for given broker
-                  u8"Room/My room/Props/Arduino Blink/inbox",
-                  u8"Room/My room/Props/Arduino Blink/outbox",
-                  "192.168.1.53", // your MQTT server IP address
-                  1883); // your MQTT server port;
+                u8"Room/My room/Props/Arduino Blink/inbox",
+                u8"Room/My room/Props/Arduino Blink/outbox",
+                "192.168.1.53", // your MQTT server IP address
+                1883); // your MQTT server port;
 ```
 
 
diff --git a/help/PropAction.md b/help/PropAction.md
index dac1731..6c3149d 100644
--- a/help/PropAction.md
+++ b/help/PropAction.md
@@ -1,6 +1,6 @@
 # *PropAction* class reference
 
-*PropAction* brings asynchronous-like behavior to sketch `loop()`.
+*PropAction* (see <a href="https://github.com/xcape-io/ArduinoProps/blob/master/src/PropAction.h" target="_blank">`PropAction.h`</a>) brings asynchronous-like behavior to sketch `loop()`.
 
 
 ## Constructors
diff --git a/help/PropData.md b/help/PropData.md
index b2d79c9..1619740 100644
--- a/help/PropData.md
+++ b/help/PropData.md
@@ -4,7 +4,7 @@
 
 See [**4. Application protocol for escape room 2.0 prop**](../README.md#4-application-protocol-for-escape-room-20-prop) in [README.md](../README.md).
 
-*PropData* is an interface (base class) implemented by 4 classes:
+*PropData* (see <a href="https://github.com/xcape-io/ArduinoProps/blob/master/src/PropData.h" target="_blank">`PropData.h`</a>) is an interface (base class) implemented by 4 classes:
 * ***PropDataDecimal*** 
 * ***PropDataInteger*** 
 * ***PropDataLogical***